Ticket #5470: activerecord_ddl_transactions.diff

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -48 +48 @@
-        true
-      end
-
+      # Does this adapter support DDL rollbacks in transactions?  That is, would
+      # CREATE TABLE or ALTER TABLE get rolled back by a transaction?  PostgreSQL,
+      # SQL Server, and others support this.  MySQL and others do not.
+      def supports_ddl_transactions?
+        false
+      end
+      
-      # Should primary key values be selected from their corresponding
-      # sequence before the insert statement?  If true, next_sequence_value
-      # is called before each insert to set the record's primary key.

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -107 +107 @@
-        true
-      end
-
+      def supports_ddl_transactions?
+        true
+      end
+
-      def table_alias_length
-        63
-      end

activerecord/lib/active_record/migration.rb

@@ -331 +331 @@
-        next if irrelevant_migration?(version)
-
-        Base.logger.info "Migrating to #{migration_class} (#{version})"
-
-
+
+
+
+
+
+
+
+
+
+
+
-      end
-    end
-
@@ -347 +356 @@
-
-        down? ? migrations.sort.reverse : migrations.sort
-      end
+
+      # Wrap the migration in a transaction only if supported by the adapter.
+      def ddl_transaction(&block)
+        if Base.connection.supports_ddl_transactions?
+          Base.transaction { block.call }
+        else
+          block.call
+        end
+      end
-      
-      def assert_unique_migration_version(migrations, version)
-        if !migrations.empty? && migrations.transpose.first.include?(version)